A desirable manner of increasing the efficiency and the specific power output of a gas turbine power plant of turbo-dynamic type is to increase the temperature of the operating cycle. This will, however, impose heavy demands upon the strength of the high temperature components, especially upon the first turbine stage, which at temperatures of about 1000.degree.C and thereabove preferably should be provided with efficient air cooling, depending upon the requirements for long working life, operational conditions and selection of materials.
The supply of the air necessary for cooling will, at the actual high operating temperatures, be a severe problem, either calling for an extensive, separate cooling system, or consuming too large a portion of the comparatively warm air from the compressor, which is valuable for the gas generation.